An air conditioner has been known in which an outdoor unit provided with a compressor and an outdoor heat exchanger, a plurality of indoor units having indoor heat exchangers, respectively, and a relay portion connecting the outdoor unit and the indoor unit are provided, and which is capable of a cooling operation (full-cooling operation mode) or a heating operation (full-heating operation mode) with all the plurality of indoor units at the same time and a cooling operation with one indoor unit and a heating operation with another indoor unit at the same time (a cooling main operation mode in which a cooling operation capacity is larger than a heating operation capacity or a heating main operation mode in which the heating operation capacity is larger than the cooling operation capacity).
As one of such air conditioners, “an air conditioner in which,
a first branching portion, which is configured by switchably connecting one side of a plurality of indoor units to a first connection pipeline or a second connection pipeline and the other side of the plurality of indoor units are connected to a second branching portion, which is configured by connecting a second connection pipeline through a first flow-rate controller connected to the indoor unit
the first branching portion and the second branching portion being connected through a second flow-rate controller, and
a relay unit, in which the first branching portion, the second flow-rate controller, and the second branching portion are made to be built-in, is interposed between a heat source unit and the plurality of indoor units, and the heat source unit and the relay unit are connected to each other by extending the first and the second connection pipelines” is proposed (See patent Document 1, for example).
Also, “a refrigerating cycle device includes a first refrigerant cycle having at least a single compressor, at least a single outdoor heat exchanger, a first throttle device capable of changing an opening degree, a high-pressure pipeline and a low-pressure pipeline installed in a story direction of a building having several floors, and a second refrigerant cycle having a second throttle device capable of changing an opening degree, an indoor heat exchanger, a gas pipeline installed in a story direction of each floor, and a liquid pipeline and installed on a predetermined floor of a building. With the refrigerating cycle device, a first intermediate heat exchanger provided at a pipeline connected annularly to the high-pressure pipeline and performing heat exchange between the first refrigerant cycle and the second refrigerant cycle in a heating operation and a second intermediate heat exchanger provided at a pipeline connected annularly to the low-pressure pipeline and performing heat exchange between the first refrigerant cycle and the second refrigerant cycle in a cooling operation are provided” is proposed (See Patent Document 2, for example).
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2-118372 (page 3, FIG. 1)
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2003-343936 (page 5, FIG. 1)